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rurally another series of facts, relating to the effects 

 of lime in the soil. 



It is evident from the analysis of woody fibre by 

 M. M. Gay Lussac and Thenard, (which shews that it 

 consists principally of the elements of water and car- 

 bon, the carbon being in larger quantities than in the 

 other vegetable compounds) that any process which 

 tends to abstract carbonaceous matter from it, must 

 bring it nearer in composition to the soluble princi- 

 ples ; and this is done in fermentation by the absorp- 

 tion of oxygene and production of carbonic acid ; and 

 a similar effect, it will be shewn, is produced by lime. 



Wood-ashes imperfectly formed, that is wood-ashes 

 containing much charcoal, are said to have been used 

 with success as a manure. A part of their effects 

 may be owing to the slow and gradual consumption 

 of the charcoal, which seems capable, under other 

 circumstances than those of actual combustion, of ab- 

 sorbing oxygene so as to become carbonic acid. 



An April, 1803, I inclosed some well burnt 

 charcoal in a tube half filled with pure water, and half 

 with common air ; the tube was hermetically sealed. 

 I opened the tube under pure water in the spring of 

 1 804, at a time when the atmospheric temperature and 

 pressure were nearly the same as at the commence- 

 ment of the experiment. Some water rushed in ; and 

 on expelling a little air by heat from the tube, and 

 analysing it, it was found to contain only seven per 

 cent, of oxgene. The water in the tube, when mixed 

 with limewater, produced a copious precipitate ; so 



